Bearing for a section of a track

ABSTRACT

A bearing for a section of a track includes, along the track sections, profile sections which deviate from each other, especially in the form of points. A plurality of supporting points is provided with a ribbed plate, in addition to an intermediate layer made of an elasticized material disposed between the ribbed plate and an associated railway sleeper. In order to obtain identical subsidences along the sections of track, substantially each support point has an identical maximum subsidence with respect to each excavated track section.

[0001] The invention relates to a bearing for a section of a trackhaving, along the track section, profile sections which deviate from oneanother, in particular in the form of switch points, comprising aplurality of supporting points respectively provided with a base platesuch as a ribbed plate, tongue heel plate, ribbed plate with slidingbedplate or with a support frame in addition to an intermediate platemade of an elastic material disposed between the base plate and anassociated support such as a railway sleeper or concrete plate.

[0002] To ensure defined elasticities for the roadbed and at the sametime obtain a reduction of body sound, elastic intermediate plates aredisposed between the the base plates, such as ribbed plates, housing thetrack and the support, such as sleepers or concrete plates, it beingused both in macadam construction and also in a solid roadway. Theelastic intermediate plates used may consist of cellular elastomers suchas PU foams which have a spring rigidity which is approximately linearlydependent on the bearing surface of the base plate. The support pointsextending along a track, in particular in the area of a point, havevarious rigidities, depending on whether or not they are situated at thestart of the point or at the end of the point.

[0003] A deflection curve results in the rail for a wheel passingthrough a track, said deflection curve being essentially dependent onthe moment or resistance or inertia of the rail section over which thewheel load is being cleared, as well as the spring rigidity of thesupporting point which, in turn, can be influenced by the elasticity ofthe intermediate plate. The base plate, such as a ribbed plate, of thesupporting point is thereby usually dimensioned in such a way that awheel load is transmitted without deformation of the base plate.

[0004] Consequently, the spring rigidity of a track, which results fromthe quotient consisting of wheel load and subsidence, deviates in thetrack from that of a point or a crossing.

[0005] A rail arrangement having an elastic intermediate plate can befound in DE 198 23 812 A1 which consists of a one-piece vulcanizate andhas an essentially even surface as well as an underside divided intozones with different properties.

[0006] DE 32 30 565 A1 relates to a rail base for switch constructionwhich consists of sections of individual plates connected by welding.

[0007] A bearing for a section of track is known from DE 298 07 791 U1which has projections cut out at the support end which extend at adistance from the supporting surface during the normal introduction offorce.

[0008] The object of the present invention is to improve a bearing ofthe aforementioned type for a section of track which has rail sectionsthat deviate from one another in their profile sections, in particularin the form of a point in such a way that track-like conditions result,i.e. the deflection curve in the area e.g. of a point or crossingcorresponds to that in the normal track.

[0009] According to the invention, the object is solved essentiallythereby that each or essentially each supporting point of the tracksection has the same maximum subsidence, taking the rail section orsections cleared from it into consideration. This means that theintermediate plate is disigned with respect to the moment of resistancewhich is essentially determined by the rail section supported on thebase plate or the rail sections supported thereon, in such a way thatthe same or essentially the same maximum subsidence results along thetrack section in each supporting point when a wheel travels through thetrack section.

[0010] In particular, it is provided that the respective intermediateplate has a surface extension clearing the base plate which isindependent of the load-clearing base surface of the base plate facingthe intermediate plate for supporting points intended for rail sectionshaving the same moment of resistance. In other words, an elasticintermediate plate which always has the same clearing surface extendsbelow the base plate independent of its surface extension.

[0011] In a further embodiment of the invention, it is provided that theintermediate plate braces the base plate essentially in its front endarea vis-à-vis the support when there is no wheel load.

[0012] The intermediate plate itself should have bone-shaped recessesextending along each longitudinal edge in the central area which extendat least symmetrically to the transverse axis, in particular, alsosymmetrically to the longitudinal axis of the intermediate plate.

[0013] The geometry of the recesses is preferably selected in such a waythat each recess has a length 1_(a) parallel to the transverse axis ofthe base and that two recesses disposed in a row extending parallel tothe transverse axis have a distance 1_(z), with1.1×1_(a)≦1_(z)≦1.5××1_(a). The recesses are thereby limited by acontinuous section of the intermediate plate which extend in a set backmanner during usual, i.e. not inadmissible wheel loads relative to thefree outer surface of the sections of the intermediate plate extendingat the front end and supporting the base plate. This also ensures asecure support of the base plate directly below the rail sectionproceeding from the base plate, so that inadmissible stresses areexcluded.

[0014] Furthermore, it is provided that a U-shaped further recess ismade in the intermediate plate in the respective transverse edge areaadjoining the recesses having a bone-shaped geometry, the longitudinalside of said recess having a maximum width which corresponds to thelength of the respective peripheral recess.

[0015] Further details, advantages and features of the invention can befound not only in the claims, the features that can be foundtherein—alone or in combination—but also in the following description ofpreferred embodiments that can be found in the drawings, showing

[0016]FIG. 1 a top view onto a ribbed plate,

[0017]FIG. 2 a bottom view of the ribbed plate of FIG. 1,

[0018]FIG. 3 a section along the line A-A in FIG. 1,

[0019]FIG. 4 a section along the line B-B in FIG. 1,

[0020]FIG. 5 a section along the line C-C in FIG. 1,

[0021]FIG. 6 a top view onto a ribbed plate with a sliding bedplate,

[0022]FIG. 7 a bottom view of the ribbed plate of FIG. 6,

[0023]FIG. 8 a section along the line A-A in FIG. 7,

[0024]FIG. 9 a section along the line B-B in FIG. 7,

[0025]FIG. 10 a top view onto a ribbed plate with support frame,

[0026]FIG. 11 a bottom view of the ribbed plate of FIG. 10,

[0027]FIG. 12 a section along the line A-A in FIG. 11, and

[0028]FIG. 13 a section along the line B-B in FIG. 11.

[0029] Elements of supporting points along a switch point can be foundin the figures without these restricting the leaching according to theinvention. Rather, this applies quite generally to track sections inwhich the supporting points with the rail sections supported thereonhaving moments of resistance that deviate from one another. Based on theteaching of the invention, however, the same maximum subsidence resultsin each support point when a wheel with the same load travels throughit. According to the invention, this is accomplished by placing anelastic intermediate plate between the respective ribbed plate and thesupport, such as a sleeper or concrete plate, which is primarilydesigned on the basis of the moment of resistance of the rail sectionsupported on the ribbed plate or the supported rail sections such asstock rail and tongue rail to ensure the same maximum subsidence. It isthereby assumed that the ribbed plate is dimensioned in such a way thatthe wheel load is passed through without deformation of the ribbedplate. Otherwise, the moment of resistance would also be taken intoconsideration when designing the intermediate plate for carrying out theteaching of the invention.

[0030] A ribbed plate 10 is shown in FIG. 1 which is disposed, forexample, at the start of a switch point. A stock rail (not shown) which,in turn, extends between ribs 12, 14, 16, 18 and is held down bystrainers (not shown), is fastened to it. The ribbed plate 10 itself isjoined to the support, such as a sleeper or concrete plate, via screwspassing through openings 20, 22.

[0031] On the bottom, the ribbed plate 10 is provided with an elasticintermediate plate 24. The intermediate plate 24 can thereby completelysurround the ribbed plate 10 both on the bottom and also on the ends, asillustrated in the sectional representations of FIGS. 3-5. Theconnection between the intermediate plate 24 and the ribbed plate 10 canbe produced by vulcanization.

[0032] As can be seen in FIGS. 3 and 4, the ribbed plate 10 is supportedby front end sections 26, 28 of the intermediate plate 24. When theribbed plate 10 is unloaded or cleared of normal wheel loads, thesections 32 between said front end sections extends at a distance fromthe bearing surface 34 of the intermediate plate 24 which can correspondto the surface of a sleeper or a concrete plate or to a plate directlysupporting the intermediate plate 24. However, in this respect,reference is made to sufficiently known constructions.

[0033] The section 32 itself is composed of a central section 36 as wellas sections 46, 48, 50, 52, 54, 56 extending between recesses 38, 40,42, 44 which together form the section 32. Furthermore, an additionalrecess 60, 62, rectangular in a top view, extends diagonally to thelongitudinal axis 58 of the intermediate plate 24 between section 32 andthe front end regions 30, 28, respectively.

[0034] The recesses 38, 40, 42, 44 extending in the longitudinal endregion have a bone shape and are disposed symmetrically, both to thelongitudinal axis 58 and to the transverse axis 64 of the intermediateplate 24.

[0035] The recesses 38, 40, 42, 44, 60, 62 produce an overall supportsurface of the intermediate plate 24 and thus a rigidity, such that themaximum subsidence of a supporting point given by the ribbed plate 10attains a desired value which is also predetermined by other supports inthe area of the point as characteristic quantity, even if the moment ofresistance or inertia of the rail sections supported thereon deviatefrom the arrangement according to FIGS. 1-5. This is obtained therebythat, when increasing the moment of resistance of the permanent way, therigidity of the corresponding intermediate plate is reduced accordingly,by diminishing the maximum supporting surface or using an intermediateplate material having another elasticity.

[0036] In other words, according to the invention, it is provided thatthe intermediate plate is made softer with increasing moment ofresistance of the supporting rail section or sections.

[0037] In FIGS. 6-9, a ribbed plate 66 with integrated sliding bedplate68 is shown along which an elastic intermediate plate 72, comprising itsunderside and its edge 70, is disposed which supports the ribbed plate66 essentially in the peripheral area when there is no load or a normalload, whereas section 74 in the centre extends at a distance from a base76.

[0038] According to the embodiment of FIGS. 1-5, the section 74 limitsbone-shaped recesses 78, 80, 82, 84 which extend symmetrically to thelongitudinal axis 86 and to the transverse axis 88 of the intermediateplate 72. On the edge, U-shaped recesses 86, 88 are provided which areactually composed of two U-shaped base sections 90, 92 and L-shapedsections 94, 96, 98, 100 extending at a distance from them, whose sides104, 106, 108 and 110 extending parallel to the transverse axis 88having an extension which corresponds to that of the recesses 78, 80,82, 84 parallel to the transverse axis 88 of the intermediate plate 72.The recesses 78, 80, 82, 84, 86, 88 are limited by the section 74 of theintermediate plate 72 as is illustrated by a comparison of the top viewonto intermediate plates 72 of FIG. 7 with the sectional representations8 and 9.

[0039] Just as the recesses 38, 40, 42, 44 of FIGS. 1-5, the innerrecesses 78, 80, 82, 84 which extend in direct vicinity of thetransverse axis 88, have a bone shape. As a result, the sections of theintermediate plate 72 extending between the recesses 78, 80, 82, 84 arecircular in a top view. The same geometry applies relative to the areasextending between the L-shaped recesses 94, 96, 100, 102 and theadjacent recesses 78, 80, 82, 84.

[0040] The recesses 78, 80, 82, 84 having a bone-shaped geometry or thesides 104, 106, 108, 110 extending parallel to the transverse axis 88have a length 1_(a) which is less than the distance 1_(z) between therecesses 78, 82 or 80, 84, respectively. This distance 1_(z) is about20-50% greater than the length of the recesses 1_(a).

[0041] Due to the greater moments of resistance of the rail sectionssupported on the ribbed plate 66 with sliding bedplate 68, i.e. stockrail and tongue rail, in comparison to the moment of resistance of thestock rail fixed to the ribbed plate 10, the intermediate plate 72 has alower rigidity than the intermediate plate 24 of FIG. 2.

[0042] If the moment of resistance of a rail section in a supportingpoint is even greater, then the rigidity of the intermediate plate iseven further reduced accordingly, as is going to be shown with referenceto FIGS. 10-13. Thus, a ribbed plate 112 with a support frame 114 isshown from which a guide rail proceeds. In other words, the ribbed plate112 is disposed in the region of a frog. According to the embodiment ofFIGS. 1-9, an elastic intermediate plate 116 which surrounds the ribbedplate 114 on the periphery (edge 118 of the intermediate plate 116 inFIG. 10) extends along the underside of the ribbed plate 112. Theintermediate plate 116 also has peripheral sections 118, 120 via whichthe ribbed plate 112 is usually cleared. Bone-shaped recesses 122, 124or U-shaped recesses 126, 128, 130, 132 are provided in the centralregion of the ribbed plate 112, the U-shaped recesses 126, 128corresponding to the recesses 86, 88 of FIG. 7. The geometry of thebone-shaped recesses 122, 124 corresponds to that of the previouslydescribed embodiments, which produces a symmetrical arrangement to thelongitudinal axis 134 of the intermediate plate 116. A section 136 ofthe intermediate plate 116 also extends between the recesses 122, 124,126, 128, 130, 132, said section extending in a set back manner relativeto the peripheral sections 118, 120 during normal wheel loads which acton the ribbed plate 112, as the sectional representations of FIGS. 12and 13 show.

[0043] Independent hereof, however, the rigidity of the intermediateplate 116 is selected in such a way that the maximum subsidence of awheel passing through the supporting point predetermined by the ribbedplate 112 corresponds to the supporting point comprising the ribbedplates 10 and 66.

1. A bearing for a section of a track having, along the track sections, profile sections which deviate from one another, in particular in the form of a switch point, comprising a plurality of supporting points respectively provided with a base plate (10) such as a ribbed plate, optionally provided with a sliding bedplate or with a support frame, in addition to a rectangular intermediate plate (24, 72, 116) made of an elastic material disposed between the base plate (10, 66, 68, 112, 114) and an associated support having a bearing surface (34), such as a railway sleeper or concrete plate, with transverse edges extending in longitudinal direction of the track section and with longitudinal edges extending diagonally to the track section which extend along the longitudinal axis of the intermediate plate, each or essentially each supporting point having an identical maximum subsidence with respect to each cleared track section or track sections by support by adjusting spring rigidity of the intermediate plate and moment of resistance of the track section supported on the supporting point, characterized therein that the intermediate plate (24, 72, 116) has a a first section surrounding the base plate on the edge and suuporting it on the bearing surface (34) and a second section (32) within the first section spaced from the bearing surface when the base plate is cleared from unloaded or common wheel loads and that the second section has recesses (38, 40, 42, 44, 78, 80, 82, 84, 122, 124) with a bone-shaped geometry extending in the central region of the intermediate plate proceeding from each longitudinal edge symmetrically to the longitudinal axis of the intermediate plate which are limited by a continuous third section (34, 76) of the intermediate plate which is spaced from the bearing surface when the base plate is clearing unloaded or common wheel loads.
 2. The bearing according to claim 1, characterized therein that the recesses (38, 40, 42, 44, 78, 80, 82, 84) are disposed symmetrically to both the longitudinal axis (58, 86) and to the transverse axis (64, 88) of the intermediate plate (24, 72) extending in direction of the track section.
 3. The bearing according to at least one of the preceding claims, characterized therein that each recess (38, 40, 42, 44, 78, 80, 82, 84, 122, 124) with a bone-shaped geometry has a length la extending in direction of the track section and that recesses disposed in a row extending parallel to the transverse axis (64, 88) have a distance 1_(z) with 1.1×1_(a)≦1_(z)≦1.5×1_(a).
 4. The bearing according to at least one of the preceding claims, characterized therein that the intermediate plate (24, 22) has a U-shaped further recess (86, 88, 126) in the respective transverse end region adjacent to the recesses (78, 80, 82, 84, 122, 124) having a bone-shaped geometry, the longitudinal side of said U-shaped further recess having a maximum width which corresponds to the length 1_(a) of the bone-shaped recess.
 5. The bearing according to claim 1, characterized therein that supporting points for rail sections with the same moment of resistance have elastic intermediate plates (24) with the same load-clearing surface whose extension is independent of the bottom surface of the base plate facing the intermediate plate.
 6. The bearing according to at least one or the preceding claims, characterized therein that supporting points for rail sections with different moments of resistance have intermediate plates (24, 72, 120) with different rigidities. 